1. Field of the Invention
The present invention relates to cytology, the study of individual cells, and, more particularly, to screening collections of cells that have been taken from a medical patient for the purpose of medical diagnosis.
2. The Prior Art
Ordinarily, such a collection of cells, after being acquired by biopsy or aspiration, are spread on a glass slide, stained and preserved, and examined under a microscope by a cytologist, i.e. a cytotechnologist or a cytopathologist. One such procedure is called a pap smear, which is a screening test for uterine cancer. This procedure usually involves wiping the cervix of a patient to collect cells, smearing the cells onto a glass slide, and sending the resulting specimen to a laboratory. At the laboratory, a cytologist stains the specimen and examines the cells under a microscope for evidence of morbidity. The microscopic examination consists of moving the slide under the microscope in a series or raster of sequential scans. During scanning and while under the microscope, atypical cells are marked with ink dots or other symbols for later identification. This scanning procedure must be performed with unremitting attention, lest the cytologist miss cells with significant abnormalities. Because distances between cells and gradients between scans are microscopic, any interruption in or distraction from the screening process may result in omissions during a scan or in confusion between scans.